Driving Under The Influence 

Of Alcohol Or Drugs

It is unlawful and punishable, as provided in 61-8-442, 61-8-714, and 61-8-731 through 61-8-734, for a person who is under the influence of alcohol to drive or be in actual physical control of a vehicle upon the ways of this state open to the public a dangerous drug to drive or be in actual physical control of a vehicle within this state any other drug to drive or be in actual physical control of a vehicle within this state alcohol and any dangerous or other drug to drive or be in actual physical control of a vehicle within this state.

See Montana Code 61-8-401.